The Japanese know well about such cataclysmic events as earthquakes, typhoons, floods, volcanic eruptions and tsunami, and fully empathize when other parts of the world suffer such catastrophes. But what do they have to say about heat domes — beneath which the mercury hits 45 degrees Celsius or higher — a phenomena from which they have so far been spared?

On June 29, the Canadian village of Lytton, British Columbia, recorded a record-setting high temperature of 49.6 C. Along with several hundred deaths, the heat caused numerous forest fires, possibly dooming the town’s very existence.

Akira Mori, president of Tokyo-based Weather Map Co., Ltd. was unable to conceal his astonishment.

“At first, I thought something had to be wrong with the data,” he tells the July 26 edition of Weekly Playboy. “This is not some desert in the interior, but a coastal area. In normal years it’s a pleasant place to spend the summer. For temperatures to approach nearly 50 C is unthinkable.”

The high temperatures were attributed to a phenomenon called a heat dome. It’s caused when westerly winds deviate from their usual meandering pattern, to form a pattern shaped like the Greek letter omega, which traps the heat and allows it to accumulate, with high-pressure air descending from above and compressing the heat as it nears the ground.

Looking at the wind direction this year, warm air from the interior of the continent crossed the Rocky Mountains to create a Foehn effect of superheated air.

“It’s believed a perfect storm of phenomena occurred coincidentally, creating several days of misery for people in the Pacific Northwest,” Mori explained.

With some trepidation, the magazine asks Mori of the possibility of such a thing ever happening in Japan.

“Actually, something approaching that has been occurring,” he replies. It seems that while the temperatures didn’t rise to 50 C in Japan, when two high-pressure zones — one from the Tibetan Plateau and one over the Pacific — overlap, the results could be described as something similar to a heat dome. In 2018, Kumagaya, Saitama Prefecture, posted Japan’s highest recorded temperature, of 41.1 C. This figure was matched two years later in Hamamatsu, Shizuoka Prefecture.

“In recent years, temperatures exceeding 40 C have been occurring on an annual basis,” Mori points out. “At that time, we tend to focus only on the highest temperature, but in Japan, with its high humidity, it’s the daily low temperatures that are scarier. When temperatures at night remain above 25 C, these are referred to as ‘tropical nights.’ Recently, there have been days when the temperature never went below 30 C. So apart from the coronavirus, it’s yet another good reason for people to stay home and protect themselves from intense heat.”

While the rainy season may not have officially ended in Kanto ahead of July 23, the opening day of the Olympics, the hot weather that typically follows it is already here.

Out of consideration to athletes’ health, the marathon events were moved north to Sapporo, with the women’s and men’s marathons scheduled to be held Aug. 7 and 8, respectively. While normally cooler than Tokyo, Sapporo has also been known to get pretty steamy: its all-time high temperature of 36.2 C was recorded Aug. 7, 1994. But of the top 10 hottest days ever recorded there, six occurred between Aug. 5 and 10 in various years.

Sports fans should all pray that the marathon’s host city is spared from abnormal heat, under a dome or otherwise.

Goods for chilling out

This summer may be remembered for the spread of the delta variant, and for those of us who are stuck in place, the July 27 edition of Friday magazine introduces 17 consumer items to help make the days a bit more bearable. In addition to a draft beer server and shaved ice maker for making snow cone confections, the magazine introduces an assortment of eye goggles, air circulator fans and bath additives.

For the ultimate in high-tech devices to cool the body, Sunday Mainichi introduces the latest gadget from Sony, the Reon Pocket 2, which went on sale from April 22. Described as a “semiconductor module” measuring 116 millimeters long, 54 mm wide and 20 mm thick, it’s worn just below the back of the neck while engaged in such activities as playing golf or driving.

Two and a half hours of recharging by USB cable provides a maximum of four hours use. According to data from the manufacturer, in a room with an ambient temperature of 30 C, body surface temperature is reduced by 13 C. But the all-season unit can also be set to impart warmth in the winter.

A smartphone app is provided free to purchasers, enabling temperatures to be set in four increments. Set to the auto mode, a built-in sensor responds to temperature or movement and performs adjustments automatically.

Reon Pocket sells for ¥14,850. But does it really work to cool the wearer? I fired off an e-mail to my smart brother, the doctor, who surmised how he supposed the device functions in authentic medical technobabble.

“It would appear to stimulate the temperature receptors of the lower cervical and upper thoracic dermatomes,” he replied. “But it may also work by inhibiting the cervical ganglia at the base of the neck and cause vasoconstriction, which would make you feel cool. It’s hard to tell from the description.”

Big in Japan is a weekly column that focuses on issues being discussed by domestic media organizations.

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